Project Title Computerized Rotational Head Impulse Test-Vertical crHIT Project Summary This proposal extends the proof of concept achieved in our SBIR Phase I studies. The goal of this Phase II SBIR proposal is to develop a clinically-suitable version of the hardware and software and test 120 control subjects and 66 patients to support the functionality of the vertical crHIT test for clearance by the FDA and commercial use. The immediate goals of this Phase II SBIR are described by the five Specific Aims of this application. The first aim is to build two retrofit kits for the FDA-approved I-Portal Neuro-Otologic Test Center (NOTC) and one lower-cost, next-generation NOTC system capable of running vertical and horizontal crHIT. These systems will be installed in three Medical Centers: University of Pittsburgh Medical Center, Miami Medical Center and Mayo Clinic. The second specific aim will concentrate on developing a method for aligning each patient's head for testing all canals and clinical software integrated to hardware with the test protocol in the commercially-available VEST? software. The third specific aim will focus on clinical testing. Total population to be enrolled in this study: 120 controls and 66 patients for a total study cohort of 186 subjects. 66 patients will include: 30 with surgically confirmed unilateral loss for validation, 15 with absent ice water calorics from vestibular neuritis, and 21 with diagnosed vestibular migraine for evaluation sensitivity and specificity of test. During clinical testing we also plan to evaluate subject's discomfort with these stimuli. The focus of the current experiments will be to obtain an evaluation of general comfort level and the potential for the vertical crHIT stimuli to evoke motion sickness symptoms. After testing and data analysis are complete we will submit results of testing to the FDA for 510K clearance (specific aim #4). FDA approval will allow us to commercially sell the vertical crHIT test to vestibular and concussion clinics. Specific aim #5 is the final report.